An optical instrument is an instrument used to move light along a specified path or paths. Microscopes are common, general-purpose optical instruments. Other optical instruments include interferometers and spectrophotometers.
Microscopes are generally used to view objects that are too small to be seen by the unaided eye. Optical microscopes use visible light and a system of lenses to magnify images of small objects. Optical microscopes are used in observing small structures, determining pathology and diagnosing disease.
There are two basic configurations of the conventional optical microscope, the simple (one lens) and compound (many lenses). There are also several different types of microscopy including brightfield, darkfield, fluorescence, and other forms. Each of these forms of microscopy are performed individually and one at a time. High magnification optical microscopes are often heavy and take up much volume.
There is a need for improved optical instruments to better diagnose pathologies and disease.